Compute (a*b)%m FAST for 64-bit unsigned arguments in C(++) on x86-64 platforms?

I'm looking for a fast method to efficiently compute  (a⋅b) modulo n  (in the mathematical sense of that) for a, b, n of type uint64_t. I could live with preconditions such as n!=0, or even a<n && b<n.

Notice that the C expression (a*b)%n won't cut it, because the product is truncated to 64 bits. I'm looking for (uint64_t)(((uint128_t)a*b)%n) except that I do not have a uint128_t (that I know, in Visual C++).

I'm in for a Visual C++ (preferably) or GCC/clang intrinsic making best use of the underlying hardware available on x86-64 platforms; or if that can't be done for a portable inline function.